A test handler is an apparatus for assisting a tester to test semiconductor devices fabricated through a manufacturing process. The test handler classifies the semiconductor devices into several classes according to their test results and loads those classified devices into customer trays.
FIG. 1 is a conceptual plan view of a general test handler 100 including a test handler in accordance with the present invention. The test handler 100 includes a loading unit 110, a soak chamber 120, a test chamber 130, a desoak chamber 140, an unloading unit 150, and so forth.
The loading unit 110 loads untested semiconductor devices in a customer tray into a test tray which is waiting at a loading position LP.
Then, in the soak chamber 120, the semiconductor devices loaded in the test tray transferred from the loading position LP are pre-heated or pre-cooled under test environment conditions before they are transferred to the test chamber 130 to be tested therein. In general, the semiconductor devices are used in various temperature environments. Thus, a test needs to be conducted to investigate whether the semiconductor devices are usable in such various temperature environment conditions. In the soak chamber 120, the semiconductor devices are pre-heated or pre-cooled to be subject to such various environment conditions. The pre-heating or pre-cooling in the soak chamber 120 is carried out while the test tray is being transferred toward the test chamber 130.
In the test chamber 130, the test tray, which has been transferred to a test position TP after being pre-heated or pre-cooled in the soak chamber 120, is brought into close contact with a tester 21 docked (coupled) to the test chamber 130, whereby the semiconductor devices loaded in the test tray are supplied to the tester 21 (more specifically, the semiconductor devices are brought into contact with contact sockets of the tester) so that the test can be carried out. Inside the test chamber 130, a temperature environment in accordance with test conditions is created.
In the desoak chamber 140, the pre-heated or pre-cooled semiconductor devices, which have been transferred from the test chamber 130 while being loaded in the test tray, are allowed to recover their temperatures.
The unloading unit 150 classifies the tested semiconductor devices in the test tray, which has been transferred from the desoak chamber 140 to an unloading position UP, into several classes depending on their test results and unloads them into customer trays.
As described above, the semiconductor devices are transferred through a path from the loading position LP to the unloading position UP via the soak chamber 120, the test position TP in the test chamber 130, and the desoak chamber 130, as indicated by an arrow “a”. The transfer of the semiconductor devices from the loading position LP to the unloading position UP is carried out while the semiconductor devices are loaded in the test tray, as described above.
Accordingly, the test tray also needs to be transferred through a circulation path, as indicated by an arrow “b”, along which the test tray starting from the loading position LP returns back to the loading position LP after passing through the soak chamber 120, the test position TP in the test chamber 130, the desoak chamber 140, and the unloading position UP.
The test handler 100 having the aforementioned basic circulation paths can be classified into two types depending on how the semiconductor devices loaded in the test tray are brought into contact with the contact sockets of the tester: one is an under head docking type and the other is a side-docking type. A side-docking type test handler allows the semiconductor devices loaded in the test tray to contact with the contact sockets while keeping the test tray vertically. Accordingly, in the side-docking type test handler, a process for changing the posture of the test tray from a horizontal state to a vertical state needs to be conducted after the loading of the semiconductor devices is completed, and a process for changing the posture of the test tray from the vertical state to the horizontal state is required after the test of the semiconductor devices is completed.
Korean Patent Laid-open Publication No. 1999-0077466 (Reference Document), entitled “Method for transferring a test tray in a horizontal type test handler”, discloses a technique related to a circulation path of a test tray in a side-docking type test handler.
The method for transferring the test tray disclosed in the Reference Document includes the steps of: changing the posture of the test tray loaded with semiconductor devices to a vertical state before the test tray is transferred into a soak chamber (in the Reference Document, the soak chamber is defined as a heating chamber); transferring the test tray into the soak chamber while keeping the test tray vertically; heating the semiconductor devices under test conditions while transferring the test tray step by step inside the soak chamber; supplying the heated test tray to a test unit while keeping the test tray vertically; transferring the test tray into a desoak chamber (in the Reference Document, the desoak chamber is defined as a cooling chamber) while keeping the test tray vertically after the test of the semiconductor devices is completed; cooling the semiconductor devices to an exterior temperature while transferring the test tray step by step inside the desoak chamber; extracting the vertically postured test tray from the desoak chamber and changing the posture of the test tray from the vertical state to a horizontal state; transferring the horizontally postured test tray to an unloading position; and transferring the test tray to a loading position horizontally after the semiconductor devices are unloaded.
In the Reference Document, the posture of the test tray loaded with the semiconductor devices is changed to the vertical state before the test tray is transferred to the soak chamber and then the vertically postured test tray is transferred into the soak chamber; and, inside the soak chamber 120, the test tray is transferred toward the test chamber while keeping the test tray vertically. However, such a method has problems as follows.
First, the circulation path disclosed in the Reference Document requires a step of transferring the test tray, which has been loaded with the semiconductor devices, to a position above the soak chamber and a step of transferring the vertically postured test tray from the inside of the desoak chamber to a position above the desoak chamber are additionally employed. However, these steps require additional time which is irrelevant to the process of heating or cooling the semiconductor devices under test environment conditions to maintain them suitable for test conditions or the process of recovering the temperature of the semiconductor devices. Thus, the efficiency of processing the semiconductor devices is deteriorated as much as the time required for these additional steps.
Second, the time required for changing the posture of the test tray to the vertical state or to the horizontal state is also irrelevant to the process of heating or cooling the semiconductor devices in the test environments to maintain them suitable for the test conditions or the process of recovering the temperature of the semiconductor devices. Thus, the posture changing step results in a deterioration of the processing efficiency.
Third, in the Reference Document, since test tray is transferred step by step inside the soak chamber and the desoak chamber while they are kept vertically, the soak chamber and the desoak chamber need to have sufficient forward-backward lengths in order to obtain sufficient time during which the semiconductor devices loaded in the test tray are heated or cooled or the temperature of the semiconductor devices is recovered. Therefore, the forward-backward length of the test handler is lengthened, resulting in an increase of the entire apparatus size.
Fourth, in accordance with the Reference Document, since the test tray loaded with the semiconductor devices is transferred in the soak chamber and the desoak chamber while it is kept vertically, a transfer path along which the test tray is moved in the vertical state is lengthened. In general, if such transfer path is long, there is a high likelihood that the semiconductor devices loaded in the test tray are separated from the test trays or deviated from their set positions inside the test tray.